Process for the recovery of textile fibers from motor vehicle tires



' Jan. 23, 1968 s. V/(RADY ETAL 3,364,526 PROCESS FOR THE RECOVERY OF TEXTILE FIBERS FROM MOTOR VEHICLE TIRES Filed Dec. 4, 1962 v 4 SheetsSheet 1 I mananumul Fig.

7 Jan 23, 1968 s. Vl-(RADY ETAL 3,364,526

Filed Dec. 4, 1962 PROCESS FOR THE RECOVERY OF TEXTILE FIBERS FROM MOTOR VEHICLE TIRES 4 Sheets-Sheet 2 23a 9 k 90 22a Fig. 2

Jan. 23, 1968 s. VRRADY ETAL 3,364,526 PROCESS FOR THE RECOVERY OF TEXTILE FIBERS FROM MOTOR VEHICLE TIRES Filed Dec. 4, 1962 4 SheetsSheet 5 37 fie-ggogo Fig. 5

Jan. 23, 1968 s. vAfRADY ETAL 3,364,526

PROCESS FOR THE RECOVERY OF TEXTILE FIBERS FROM MOTOR VEHICLE TIRES Filed Dec. 4, 1962 4 Sheets-Sheet -1 9 F 1 I I I f 1 l I I I T' j' Fig. 8

United States Patent 3,364,526 PROCESS FOR THE RECOVERY 0F TEXTILE FIBERS FRGM MOTOR VEHICLE TIRES Sandor Varatiy, 126430 Uiloi ut, Budapest X, Hungary,

and Janos Darvas, 20/b Lovohaz utca, Budapest H, Hungary Filed Dec. 4, 1962, Ser. No. 242,236 4 Claims. (Ci. 1--82) This invention relates to a process and machinery for the comminuting of rubber textile-containing goods and the recovery of textile contents from the comminuted goods.

Rubber particles are widely used in industry, for instance, as basic material of regenerates, as an admixture to bitumen, for the production of rubber bitumen, as an ingredient of rubber compositions, for the making of elastic rubber-padding and the like. But it may be used for any other suitable purpose where its main requirement is a uniform granular structure, while not having too coarse, nor too fine grains, and being at the same time, as far as possible, free from textile impurities.

Most of the developed types of machines for milling and recovery of textile contents are the continuously operating milling machines which strive to remove the textile contents from comminuted materials by means of vibratory flat sieves or rotary screen drums. But this removal is far from being satisfactory. Textile impurities in particles ground from rubber trimmings having a high textile content still remains very high. Moreover milling of trimmings having a high textile content has a number of other drawbacks. For instance, milling machines are subjected to an intense stress, in that such machines have not only to shred, but also to break textile material of considerable strength. For this reason rubber trimmings having a high textile content are abandoned and only the bands, bare of textile contents, and the neighboring portions with small textile contents in proportion, are ground, while the carcass, the major part of the rubber tire, re mains unused. A further disadvantage of these machines is that they do not lend themselves to production of articles of desired size, except between certain limits. For instance, vibratory flat sieves cannot produce fine particles smaller than 2 mm.

Up to the present, the economic utilization of cord fibers resulting from grinding of rubber pieces, has not yet been possible, owing to the lack of proper processes and machinery.

The general object of the present invention is to overcome or mitigate the above disadvantages by providing a process, and machinery, which, combined with known processing methods, lends itself to a more economic utilization of waste rubber than was possible up to the present.

Another object of the invention is to provide a process and apparatus which completely separates the textile from the rubber, provides any desired particle size, and recovers the textile content of the waste in a state which renders possible the production of textile products of high value, such as, for instance, industrial padding, by means of further processing. A further object of the invention is to provide a process and apparatus for the utilization of rubber tires, which is more productive, economic, provides better quality and supplies also the means for the recovery of a new, valuable raw basic material.

The invention consists in a process for the production of rubber particles from rubber goods containing textiles, especially from second-hand motor vehicle tires, and for the recovery of textile contents, in which prior to comminuting the rubber and its textile contents are ripped into strips and the strips are cut crosswise to similar or substantially similar lengths and these uniform long slices of rubber, containing textile yarn, are fed in revolving grinding mills of known construction. Following the milling, the rubber particles of mixed sizes are carried to a sizing apparatus for the separation of residue of textile impurities and their removal into a separating system, while the cord fibers separated from the rubber are fed to a licker-in, and a carding willow for the purpose of recovery; the recovered staple fiber being passed into a carding machine.

The invention further consists in an arrangement of machines for carrying out the process, in which the machinery comprises a cutting machine constructed upon the operating principle of a lathe, for the ripping of rubber tires to strips, a slicing machine for the crosswise cutting of the strips, a revolving disc-type milling machine of known principle for the sizing of resulting particles and for the separation and removal of the residue of textile impurities, multi-step, slope plane, vibrating, screen-type, multi-sinker throat, separating air-piping of various hole diameters, a licker-in and carding-willow for the purpose of recovering cord fibers separated from the rubber, a carding machine with a lap winder for the coiling of the staple fibers.

The invention will now be described, by way of ex ample, with reference to the accompanying drawings, in which:

FIGURE 1 is a schematic view of the arrangement of machines according to the invention;

FIGURES 2 to 4 show in detail the operations of ripping the tires to strips and the cutting thereof to predetermined lengths;

FIGURE 5 is a schematic view of a slicing machine in side view; I

FIGURE 6 is an end view of FIGURE 5;

FIGURE 7 shows a diagrammatic view of the structure for separating rubber particles from the milling machine and air-piping for the removal of textile grinding residue;

FIGURE 8 is a diagrammatic side view of the arrangement of machines according to the invention for processing the cord fiber waste.

Referring to FIGURE 1, rubber tires are cut by a cutting lathe 1 to strips of about 20-25 cm. in width. These are cut into slabs, or segmental rings, and fed into a slicing machine 2, which chops them into relatively small slices. These slices are then fed into a comminuting or milling machine 3 of known construction, for instance, one of theCondux-type, which stores the comminuted particles in a receptacle 4- from which the stored material is carried by a screw feed conveyor 5, onto a vibrating sive 6, from where the particles go into the separating air-pipe system 7. The textile residue of the above process is led partly from the vibrating sieve 6 through a aperture 8, into the open air, and partly from the air-piping 7, into a dust cage 9. Part of the particles is fed by a screw feed conveyor 10 to sack spouts 11, and the particles smaller than 1 mm. in size leave the machine through a side hole 12.

The processing of the cord fibers starts at the rotary screen drum of the milling machine 3. The cord fibers are then conveyed by a pneumatic feeder 13 to a licker-in 14, and the partly separated cord fibers are brought by the pneumatic feeder 15 into a three-step carding-willow 16. The separated cord fibers then pass through a pneumatic feeder 17, in the stocklifter 18 of a carding-wil low, to a carding-willow 19, the product of which is coiled up by a roller pack 20.

With particular reference now to FIGURES 2 to 4, a rubber tire 22 is put onto a table 21 of the tire-cutting machine, and cutting tools 23 split off strips 24 and 25 from the top-side of the tire. The manner of operation of cutter 23 is as follows. First cutter 23 is lowered with its blades 23a penetrating into the sidewall 22a of tire 22, while the tire 22 is fixedly secured to a rotatable holding device 31, which has spikes inserted into the bottom sidewall 22b to prevent rotation of tire 22 with respect to holding device 31.

The spiked holding device 31 is rotatably mounted on a hub 90 which is fixedly secured to a support table 21. Holding device 31 is mounted by any conventional means to rotate about vertical axis 91, while vertically extending cutter assembly 23 is secured to support table 21, against rotative motion, by any conventional means (not shown). A second cutting tool 26 has a horizontally extending blade 26a which may be extended to and from the tread wall 22c, so as to have blade 26a penetrate into tread wall 220. Horizontal cutting tool 26 is fixedly secured to support table 21 by any conventional means (not shown). Thus, when blades 23a and 26a are extended to penetrate into walls 22a and 220 respectively, holding device 31 is rotated about axis 91, by any conventional M means, causing blades 23a and 26a to slice strips, as for example, 24 and 25 out of top sidewall 22a.

In the case of tires having a wide tread wall 22c, the second cutting tool 26 is employed as shown in FIG. 3, to have blade 26a penetrate horizontally through tread wall 220, and holding device 31 is then rotated, in a manner similar to that described with respect to cutting tool 23, to slice a. strip 27 from the tread wall 220. Following this, strips 28, 29, 30 are split oti by cutting tool 23 in a manner similar to that with respect to severed strips 24 and 25. The severed strips produced by the above cutting process may be removed by any conventional means, such as by hand or conveyor, and cut into smaller segments by any conventional cutting method (not shown), with the smaller segments then placed on the chain conveyor 32 by hand or by any conventional conveyor method.

The slicing machine is shown schematically, in side view in FIGURE 5, and in end view in FIGURE 6.

Feeding of the material into the slicing machine takes place by means of a roller chain laminated conveyer 32. A segmental ring slab 33 of the tire is put on the conveyer 32, which passes below a ribbed roller 34 which restricts sidewise deflection of strip 33 by clamping it against the conveyor. The ribbed roller 34 is raised or lowered according to the thickness of the material, and regulated by a spring 35. The peripheral speed of the ribbed roller 34 is synchronized with the feed speed of the conveyor. The strip 33 is held down by the fluted roller 36 which secures uniformity of feeding. A countersupport for the fluted roller is etfected by a roller 37; the peripheral speed of the rollers 36 and 37 being synchronized also with speed of the conveyer 32. Holding of strip 33 is effected by spring 38 through the roller 36 which presses the strip against a tool holder 39, to which a stationary cutting-tool 40 is fixed. A moving tool 43 is fixed to a rotary tool-carrier 41 by means of the tool-holding device 42 carried by the rotary tool-carrier 41. Two such moving tools 43 are fixed to the carrier 41, with an angular spacing of 180 with respect to each other. The center line of the rotary carrier 41 is parallel with the path of movement of the strip material 33. The cutting of the strip 33, or segmental ring, is effected in such a way that the stationary cutting tool 40, forms a 90 angle with the path of movement of the feed of the conveyer 32, and the moving tool 43, fixed on the rotary carrier 41, shears through the material.

The cutting curve of the moving tools edge, in relation to stationary cutting tool 40, forms in the cutting stage, at any angular displacement of the rotary carrier 41, an angle of about 20. FIGURE 6 shows that moving tool 43 has in its position shown in full lines the cutting angle which is the same as the cutting angle in the illustrated dotted-line position 43'. The cutting edge should have an angle 5 of 20-25 (see FIGURE 5). Both of the moving tools 43 of the rotary carrier 41 slice two pieces from the strip 33, at each revolution. The sliced lengths may be chosen from the range of 30-50 mm. while the speed of rotation of carrier 41 is 500 rpm. with an 8-hour output of 20 to 25 tons and a power demand of 30 HP.

Referring now to FIGURES 7 and 8, a screw feed conveyor transports the material from the storage receptacle of the milling machine onto the sieve separator 6, the ground material passing through a distributor trough 44 onto the upper sieve 46 of the upper vibrating machine 45. The pieces of granular rubber and the smaller textile impurities fall through onto the lower sieve 47, and the larger textile impurities falling into the textile offtake 48. Eccentrics S0 drive the upper vibrating machine 45 and the lower vibrating machine 49 and suspension of the vibrating machines is secured by supports 51. Only the substandard size particles, i.e. under 1 mm., fall through the sieve and are carried away through the airpiping 12, in order to avoid their being carried through the air-stream into the dust-cage. The material from sieve 47 falls onto the sieve 52 of the lower vibrating machine 49. From there the larger textile particles pass through a conduit 8a, and the rubber particles still containing the textile particles are fed from the vibrating machine 49 into the air-piping 53, where a flow is produced by means of the air-stream caused by a ventilator 54, the particles being carried by the air-stream in the piping 7. Sizing takes place according to the particles size, specific weight or trajectory, and the particles fall, according to their trajectory into the conduits 55. The textile dust drops into the dust cage 9. The quantity of particles may be regulated by the intensity of air stream.

For the processing of cord fiber waste, as an industrial product, use is made of machines, already known in the textile industry, and most suitable for adaptation, as shown in FIGURE 8. These machines branch otf from the screen drum of the milling machine.

The cord fibers are fed through a trough 56 in a pneumatic transporter and through a pipe 57 and cyclone 58 to a table 59 from where they are charged between the feeding rollers 60 of the licker-in 14. The diameter of these rollers is smaller than those used hitherto, in order to make them suitable for the processing of shorter cord fibers obtained from the tires. Rollers 60 thicken the material While feeding it to a willowing drum 61, where the first step of willowing, that is to say disintegrating, of the cord fibers takes place. Smaller pieces of rubber, if any, drop from between the rollers 60 to a chute 66 to be displaced from the machine. The disintegrated material is charged into a suction cylinder 62, where the material thickens. Thickening is furthered by air suction caused by a suction-segment 63, drawing off the dust and part of the rubber powder. The low speed of rotation of the suction cylinder makes possible the amassing of the material which is pressed together and compressed by a roller 64 to form a fleece. From there the fleece is passed onto the conveyor belt 15.

From the conveyor belt 15 the separated material passes onto a table 67 of the rnulti-step carding willow 16, then between feed rollers 68, which compress the material, conveying it to a willowing drum 69, and finally picking of the material takes place on a suction drum 70. By the slow rotation of the suction drum, the material is compressed. By operation of the ventilator 20', duct and rubber powder are carried off. The suction drum 70 and roller 72 are helpful in conveying the material between the feed roller and in the following step of the carding willow. On repeating the process, the material gradually becomes finer and cleaner, nearly absolutely free of impurities, and the opening out to staple fibers takes place. The pneumatic conveyor 17 conveys the material from supply table 73 into the storage receptacle 18. A continuous batcher 74 maintains a regular feeding gob the carding willow 19 to effect the distribution of staple ers.

The separated material is fed from the feeding table 75 between compressing rollers 76, then from a drum 77, to a carding drum 78 having a carding roller system 79, the rollers rotating in opposite directions and at low speed. This enables a distribution of the fibers. The material passes onto a doiier roll 80, then with the aid of a vibrating doffer blade 81 to a conveyor belt 82 which feeds the material into the lap winder 20, where the coiling of the product 83 is effected by rollers 84.

Advantageously the cutting machine is the carouseltype and cuts larger tires into four strips and smaller ones into three strips, in one operation, or in a sequence of operations separating at the same time the wires in the beads. The use of this machine increases the productivity of the operation by approximately percent, in comparison to processes known hitherto.

The slicing machine has a cutting tool, fixed at a right angle for the crosswise slicing of feed strips, and opposite thereto a shearing slicer, the edge of which forms, in all its positions during the shearing, a similar angle to that of the cutting tool, of about 20. This solution of slicing, while carrying a power demand lower by percent, ensures a productivity higher by 30 percent in comparison with the known rubber-slicing solutions. At the same time the cost of the machinery, owing to technical efficiency, is far cheaper than that of the known types of slicing machines. By cutting and slicing the rubber tires, to pieces roughly 56 cm. long containing cord fibers, efiicacy of the grinding mill is enhanced, and its life lengthened, by eliminating the carding of the cord fibers, so the machine has only to perform a shredding action. This circumstance increases the capacity of the grinding mill system by about 20 percent, resulting also in a more uniform and lower power demand. By the feeding of short slices, in the course of comminuting the rubber trimmings, cord fibers are separated from the rub her without their being bruised, making them suitable for the production of textile products of high value, for instance of industrial padding, by proper textile waste processing operations. Cord fibers separated by means of hitherto known milling processes were bruised and torn to pieces to such an extent that they became unsuitable for further processing. Therefore the invention increases substantially the economy of utilization of rubber trimmings by milling.

In comminuting the whole rubber tire, known milling machinery is unfit for proper separation of the cord fibers, and the production of particles having a uniform degree of fineness. A multiple-stage, vibrating, screentype, multi-sinker, throat and multi-step air-piping is therefore used with the present invention. The use of such structure for the purposes of the present invention was unknown up to the present. The application of the vibrating screen and separating air-piping provide a means to obtain particles, almost absolutely devoid of textiles and of uniform size, at any desired size in range of 0.1 to 4 mm.

The process and apparatus of the present invention improves substantially the quality of particles gained by comminuting of rubber tires, developing more widely its field of application. Particles, recovered in this way, as compared with quality of particles, fouled by textile impurities of unequal and mixed size, can be utilized more favorably for the manufacture of regenerated rubber bitumen, ingredients of mechanical rubber goods, and elastic rubber-padding. It is the cutting of the rubber tires and uniform slicing which ensures separation, without bruises, of about two-thirds of the cord-fibers, while the whole processing system developed by the invention opens the way to continuous processing of the waste, on leaving the comminuting system. Before being fed into the licker-in, the waste passes a batting machine, in order to remove the waste sticking on the cord fibers. The various elements of the textile machinery have been modified so as to adapt same to the processing of short cord fibers in the terms of the invention.

Valuable industrial padding for the upholstery, clothing, furniture, quiltmaker-industry, as well as serviceable textile starting materials, proper for admixture, may be gained by the process of the present invention.

What we claim is:

1. In a process for recovering materials from motor vehicle tires which contain rubber and textile components, the steps of cutting the vehicle tires first into circular rings and then into predetermined lengths, grinding the tire lengths in a revolving disc grinding mill into rubber and textile components, delivering the rubber components to a vibratory sieve assembly for separating the rubber components into rubber particles of different sizes, and delivering the textile components to a carding assembly and forming the same into staple fibers.

2. In a process as defined in claim 1, comprising delivering portions of said textile components to said vibratory sieve assembly together with said rubber components for separating said textile and rubber components.

3. In a process as defined in claim 2 comprising removing dust-like particles of extremely small size from said vibratory sieve assembly.

4. In a process as defined in claim 1 wherein said vehicle tire circular rings are cut into lengths of about 30 to millimeters, in the step of cutting the vehicle tire circular rings into predetermined lengths.

References Cited UNITED STATES PATENTS 2,683,901 7/1954 Griswold 1998 2,115,234 4/1938 Preston 146-409 2,901,777 9/1959 Sofio 19-82 3,098,264 7/1963 Meinicke 19-82 1,321,201 11/1919 Young 19-82 1,607 291 11/1926 Marie. 1,880,372 10/1932 Bull 19-82 2,136,099 11/ 1938 Buxbaun.

FOREIGN PATENTS 127,970 6/ 1919 Great Britain. 177,874 9/1935 Switzerland.

ROBERT R. MACKEY, Primary Examiner. DONALD W. PARKER, Examiner. 

1. IN A PROCESS FOR RECOVERING MATERIALS FROM MOTOR VEHICLE TIRES WHICH CONTAIN RUBBER AND TEXTILE COMPONENTS, THE STEPS OF CUTTING THE VEHICLE TIRES FIRST INTO CIRCULAR RINGS AND THEN INTO PREDETERMINED LENGTHS, GRINDING THE TIRE LENGTHS IN A REVOLVING DISC GRINDING MILL INTO RUBBER AND TEXTILE COMPONENTS, DELIVERING THE RUBBER COMPONENTS TO A VIBRATORY SIEVE ASSEMBLY FOR SEPARATING THE RUBBER COMPONENTS INTO RUBBER PARTICLES OF DIFFERENT SIZES, AND DELIVERING THE TEXTILE COMPONENTS TO A CARDING ASSEMBLY AND FORMING THE SAME INTO STAPLE FIBERS. 